The Yeti style mugs have an OD of 101mm (3 15/16"). The clever dripper is just a little too small at 95mm (3 3/4").
It works fine to just offset the dripper on the edge of the mug but this adapter ring is satisfying to use if you don't mind the extra piece laying around. Tabs are optional and flat to make printing simple. I just CA glued them on.
The author marked this model as their own original creation.